1. Field of the Invention
The invention discloses a safe, economical system for changing the body's circadian rhythm through the incorporation of fiber optics in combination with a light source.
2. Brief Description of the Prior
The internal systems of all animals follow a cycle regulated by hormones. These cycles are daily, monthly, and yearly and are controlled by changes in length of light vs. dark. This is commonly referred to as circadian rhythm and affects the body's rhythmic repetition of certain functions, including sleep. The internal biological Circadian clock cycles once in about 25 hours. In healthy people, the ordinary day/night visual exposure to sunlight is sufficient to reset the circadian dock each day. This mechanism is clever and simple, requiring only set point. Such a regulatory method is insufficient to make as simple a mechanical device as a house thermostat, which requires two set points, operate correctly. It is thus possible, in healthy individuals, to use strong broad band light to force melatonin suppression, thereby phase shifting their Circadian clock. Physical and emotional problems can occur in people who loose part or all of their circadian function or are unable to receive a dose of optical radiation sufficient to reset their clock.
Those who live in the Northern latitudes suffer more from clock regulation problems because the winter months the daily dose of sunshine is not sufficient for their body's internal clock to maintain synchronicity with day/night cycles. This lack of regulation can result in disruption of sleep, decreased attention span, gastrointestinal disturbances, irritability, headaches, reduced immunity, clinical depression, carbohydrate cravings, weight gains, reduced work productivity, social withdrawal, to name a few. Because many people have few or no problems during the summer, this condition is called "Seasonally Affected Disorder" (SAD).
Air travel poses increasingly common problems as the circadian cycle is upset if more than two times zones are crossed in one day. Commonly known as "jet-lag," this problem is caused because the normal clock is only reset about one hour per day. It is well known in the field that one's circadian clock can be reset by administering carefully timed doses of bright light separated by careful avoidance of the same light at other specified times.
When light is administered to the eye at specific times relative to the circadian cycle, the therapy is often called chronotherapy. Chronotherapy has been developed to treat diseases or conditions through the use of light and, for these purposes, includes controlling the Circadian Rhythm, by advancement or retardation, as it relates to the internal circadian clock. The current conventional system is a light box with eyecups. The box is highly reflective, diffused white, like the inside of an integrating sphere and contains a source, or sources, which fill the box or cavity with light. The source is shielded to prevent a direct path from the source to the retina of the eye. Therefore, the eye sees a uniform illumination field, usually broad wavelength band white, rather than a specific narrow wavelength bank or line of light. It is possible to spectrally filter a portion of the source, but the sources are generally weak and too little of the filtered light reaches the retina for a chronotherapeutic effect. With very bright sources, a light box would be versatile. light boxes are currently used for treating Seasonally Affected Disorder (SAD) and it is likely that they can be used for shifting the phase of the Circadian Rhythm. Light boxes are little used except by those who are desperate. The general population is unwilling to use a light box for the required 100 to 200 minutes per day and, especially since no other use of the eyes is possible during light box chronotherapy.
The search for a method of passive ocular chronotherapy was motivated by a desire to enable a user to undergo chronotherapy while not otherwise limit eye function. This type of chronotheral)y is dubbed "passive" because the eyes may be used for other activities, such as watching television, reading a book, performing various sight guided tasks, or driving while receiving photonic medication. One form of passive chronotherapy is to place a chronotherapeutic subject into a specifically built, light filled room, in which the subjects are exposed to carefully filtered light. These rooms are very expensive and one or more are being built at Harvard with their primary goal being to test spectral response intensity and exposure (time) effects on chronotherapy.
The disclosed device overcomes the problems associated with passive chronotherapy but providing an inexpensive, portable device that overcomes the above disadvantages.